Which species of Echinacea:
E. purpurea, E. angustifolia, and E. pallida. ???
some work and some don't.
Dunno. Maybe all. I think purpurea is the most commonly used.
E. purpurea is what I use.
Haven't had a serious cold in the 10 or so years since I started using it at the first symptoms.... And I used to get several HORRIBLE colds every year.
I swear by it.
Use the powdered natural root in capsules, not the processed pills. The processed tablets are no where near as effective.
Echinacea to ping me in here. ;')
[rimshot!]
Anecdotally, some friends of mine have tried this once upon a time and said it worked. :')